The preparation of a mixture containing cyclohexanol, cyclohexanone and cyclohexyl hydroperoxide by the air oxidation of cyclohexane with cobalt catalysts is described in Pugi U.S. Pat. No. 3,530,185 and Rapoport U.S. Pat. No. 3,957,867.
The preparation of cyclohexanone and cyclohexanol from cyclohexyl hydroperoxide by hydrogenation using as catalyst a group VIII metal deposited on an inert support is described in Nouvel U.S. Pat. No. 3,694,511.
The preparation of cyclohexanone and cyclohexanol from cyclohexyl hydroperoxide by hydrogenation using a finely divided Group VIII metal that is suspended in the reaction medium is disclosed in van de Moesdijk U.S. Pat. No. 3,927,108. In Example VI this patent shows water-washing the product of the air oxidation of cyclohexane prior to hydrogenation of the cyclohexyl hydroperoxide.
Constantini, et al U.S. Pat. No. 3,923,895 discloses a process for hydrogenation of a water-washed mixture containing cyclohexyl hydroperoxide, to form cyclohexanone and cyclohexanol using a chromium catalyst and a mono or diester of orthophosphoric acid.
It is known from Sipos European Patent Application 0063931, to carry out the air oxidation of cyclohexane using a binary catalyst system of cobalt and chromium compounds and free dialkyl phosphate.
When a mixture containing cyclohexyl hydroperoxide and cobalt catalyst is formed, for example, during the air oxidation of cyclohexane as disclosed, for example, by Pugi, the cyclohexyl hydroperoxide will react catalytically with the cobalt catalyst to form a mixture of products including cyclohexanone and cyclohexanol, but the reaction does not produce these products in high yield, and other waste products are also formed.
If a mixture containing cyclohexyl hydroperoxide and a cobalt catalyst is subjected to a hydrogenation reaction in the presence of a fixed bed hydrogenation catalyst, cyclohexanone and cyclohexanol are among the products produced, but the reactor soon becomes fouled with cobalt containing residues and with residues from other oxidation products produced during the initial oxidation reaction, i.e., diacids and hydroxy acids, and the reaction slows and the yield of desired product is reduced.